It's probably a good idea not to cross Oprah.
The talk show queen has used a lot of her considerable fortune giving to causes dear to her, like opening a school for girls in South Africa. But she's often been criticized for not doing enough for black people -- specifically black people in the United States.
On Sunday evening, one Twitter user criticized Winfrey directly.
But Winfrey shot back with a sharp retort.
It wasn't clear immediately as to which of her charitable activities in education Winfrey was referring, but she has donated a million dollars to several charter school networks across the country. She is also the largest individual donor to Morehouse College, the all-male institution that has long been of the nation's premier historically black colleges. The college said that she has donated more than $12 million since 1989.